IEEE C802.16m-09/0782
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
MAC Header Restructure
Date
Submitted
2009-04-24
Source(s)
Joey Chou
Muthaiah Venkatachalam,
Sassan Ahmadi,
Xiangying Yang,
Jose Puthenkulam,
Jie Hui,
Intel
Re:
TGm SDD: SON
Abstract
This contribution proposes text for MAC header restructure.
Purpose
Adopt proposed text.
Notice
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E-mail: joey.chou@intel.com
MAC Header Restructure
Joey Chou, Muthaiah Venkatachalam, Sassan Ahmadi, Xiangying Yang, Jose Puthenkulam, Jie Hui,
Intel
I.
Introduction
IEEE 802.16 GMH has been loaded with excessive features in the previous amendments
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IEEE C802.16m-09/0782
and revisions, In order to support many advanced features in 802.16m efficiently, the
restructure of the MAC header is needed. Here are some guidelines for the MAC header
restructure:

Reuse – 802.16m is just an amendment to 802.16Rev2 base standard; therefore,
the restructure should take into account the reuse of existing MAC management
and signaling messages.

Efficiency – The existing GMH is 6 bytes long that is extremely inefficient in
sending small singling messages. The new header structure should take into
account not only the size of the message, but also how often a message is sent.

Flexibility – It seems that a new set of features is created; a new layer identified
by the subtype is added to the existing MAC header. The new header should have
the flexibility to add new features in the future.
Since 802.16Rev2 is the base standard for 802.16m, the first thing we need to consider is
to insure the new MAC header structure is able to support the subheaders, extended
subheaders, control and signaling messages of 802.16Rev2 as shown in Figure 1 to Figure
4 below.
HT=0, EC=0
GMH UL/DL MAC
PDU with data
payload
no encryption
HT=0, EC=1
GMH UL/DL MAC
PDU with data
payload
with encryption
Type Bit #0
DL – FFSH (8 bits), UL – GMSH (7 or 16 bits)
Type Bit #1
PSH (16 or 24 bits)
Type Bit #2
FSH (8 or 16 bits)
Type Bit #3
Extended for Non-ARQ connection
Type Bit #4
ARQ feedback(variable)
Type Bit #5
Reserved
Figure 1: GMH UL/DL MAC PDU with data payload
HT=1, EC=0
UL MAC PDU w/o
payload
Type #0
BR incremental (19 bits + CID)
Type #1
BR aggregate (19 bits + CID)
Type #2
PHY channel report (19 bits + CID)
Type #3
BR with UL power report (19 bits + CID)
Type #4
BR and CINR report (19 bits + CID)
Type #5
BR with UL sleep control (19 bits + CID)
Type #7
SN report (11 bits + CID)
Type #6
CQICH allocation report (19 bits + CID)
Figure 2: UL MAC Signaling Header Type I without data payload
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IEEE C802.16m-09/0782
HT=0, EC=0
ESF = 0
No extended
subhedader
HT=0, EC=1
DL Ext SubHeader
HT=1, EC=0
HT=1, EC=1
UL Ext SubHeader
ESF = 1
Extended
subheader
Type #0
SDU_SN (8 bits)
Type #1
DL sleep control (24 bits)
Type #2
Fast feedback control (24 bits)
Type #3
SN request (8 bits)
Type #4
PDU SN short (8 bits)
Type #5
PDU SN long (16 bits)
Type #6-127
Reserved
Type #0
MIMO mode feedback (8 bits)
Type #1
UL Tx Power Report (8 bits)
Type #2
Mini-feedback (16 bits)
Type #3
PDU SN short (8 bits)
Type #4
PDU SN long (16 bits)
Type #5
Persistent allocation error event (8 bits)
Type #6
ertPS resumption bitmap (8 bits)
Type #7-127
Reserved
Figure 3: UL MAC Signaling Header Type II without data payload
Type #1
Reserved
HT=1, EC=1
DL: compressed DL-MAP
UL: MAC PDU w/o payload
Type #0
Type #0
CQI & MIMO feedback (9 bits)
Type #1
DL average CINR (5 bits)
Type #2
MIMO Coeff feedback (9 bits)
Type #3
Preferred DL Channel (8 bits)
Type #4
UL Tx Power (8 bits)
Type #5
PHY Channel feedback (18 bits)
Type #6
AMC band indication (32 bits)
Type #7
Short-term precoding feedback (4 bits)
Type #8
Multiple types of feedback (variable max 32 bits)
Type #9
Long-term precoding feedback (14 bits)
Type #10
Combined DL Avg. CINR (5 bits)
Type #11
MOMO channel feedback (32 bits)
Type #12
CINR feedback (16 bits)
Type #13
Closed-loop MIMO feedback (max 26 bits)
Type #14-15
Reserved
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IEEE C802.16m-09/0782
Figure 4: GMH UL/DL Extended Subheaders
II.
Proposed text
10.12.1MAC header formats
10.12.1.1 Generic MAC Header
Flow ID (4)
EH (1)
Length (3)
Length (8)
Figure 22 Generic MAC header format

FlowID (Flow Identifier): This field indicates the service flow that is addressed. This field is
4bits long.

EH (Extended Header Presence Indicator): When set to ‘1”, this field indicates that an
Extended Header is present following this GMH.

Length: Length of the payload. This field is 11bits long
10.12.2.1 Fragmentation and packing extended header for transport connection
This fragmentation and packing extended header is shown in Figure 25. This header shall be used
when MAC PDU contains single transport connection payload. The location of this header exists
after the last extended header ( i.e. extended header with ‘Last’ = ‘1’) if ‘EH’ in GMH set to ‘1’ or
after the GMH if ‘EH’ in GMH set to ‘0’.
Figure 25 Fragmentation and packing extended header format for transport connection

SN (10 bits): Payload sequence number

FC (2 bits): Fragmentation control bits definition is given in Table 2.

End (1 bit): If this bit set to ‘0’, another ‘Length’ and ‘End’ field are followed. If this bit set
to ‘1’, reserved bits may follow for byte alignment

Length (11bits): This field represents the length of SDU/SDU fragment. If a payload
consists of ‘N’ SDU/SDU fragments, N-1 length fields are present in the header

Rsvd: Reserved bits for byte alignment.
FC
00
01
Meaning
The first byte of data in the MPDU payload
is the first byte of a MAC SDU. The last byte
of data in the MPDU payload is the last byte
of a MAC SDU.
The first byte of data in the MPDU payload
is the first byte of a MAC SDU. The last byte
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Examples
One or Multiple Full SDUs packed in an
MPDU
a) MPDU with only First fragment of an SDU
b) MPDU with one or more unfragmented
IEEE C802.16m-09/0782
10
11
of data in the MPDU payload is not the last
byte of a MAC SDU.
The first byte of data in the MPDU payload
is not the first byte of a MAC SDU. The last
byte of data in the MPDU payload is the last
byte of a MAC SDU.
The first byte of data in the MPDU payload
is not the first byte of a MAC SDU. The last
byte of data in the MPDU payload is not the
last byte of a MAC SDU.
SDUs, followed by first fragment of
subsequent SDU
a) MPDU with only Last fragment of an SDU
b) MPDU with Last fragment of an SDU,
followed by one or more unfragmented
subsequent SDUs
a) MPDU with only middle fragment of an
SDU
b) MPDU with Last fragment of an SDU,
followed by zero or more unfragmented
SDUs, followed by first fragment of a
subsequent SDU
Table 2 Fragmentation control information
10.12.2.2 Fragmentation extended header for management connection
This fragmentation extended header is shown in Figure 26. This header shall be used when MAC
PDU contains single management message payload
Figure 26 Fragmentation extended header format for management connection

Last (1 bit): always set to ‘1’

TYPE(TBD): Extended header type field

SN (8 bits): Payload sequence number

FC (2 bits): Fragmentation control bits definition is given in Table 2.

Rsvd: Reserved bits for byte alignment.
5